基础控件：按钮

Button 是有默认宽高的。

Button {
            autoRepeat: true
            onClicked: console.log("132")
        }

反复发射信号

每一个属性都绑定了一个信号

Button {
            checkable: true
            onCheckedChanged: console.log("165146")
            onClicked: console.log("132")
        }

按下状态变化

Button {
            onDownChanged: console.log("18941")
            onClicked: console.log("132")
        }

Button {
            icon.source: "qrc:/images/save.png"
            icon.color: "red"
            text: "123"
        }

Button {
            icon.source: "qrc:/images/save.png"
            icon.color: "red"
            text: "123"
            display: AbstractButton.IconOnly
        }

RoundButton {
            anchors.centerIn: parent
            radius: 3//默认值是width/2
            icon.source: "qrc:/images/save.png"
            icon.color: "red"
            text: "123"
            display: AbstractButton.IconOnly
        }

ToolButton {
            anchors.centerIn: parent
            icon.source: "qrc:/images/save.png"
            icon.color: "red"
            text: "123"
            display: AbstractButton.IconOnly
        }